The present disclosure relates to vehicles having tail lights illuminated for nighttime and reduced visibility driving and illuminated upon application of the vehicle brakes by the operator. Currently, motor vehicles employing engines driving the wheels through an automatic transmission decelerate only moderately upon release of the engine throttle and thus require the operator to apply the brakes often in traffic; and, upon application of the brakes, the tail lights are illuminated brightly to provide a readily visible indication to the operator of a trailing vehicle that the lead vehicle is decelerating.
It has recently become desirable to propel vehicles with electric motors operating from storage batteries to reduce harmful engine exhaust emissions. However, electric motor driven vehicles, upon the operator releasing the accelerator or drive pedal and discontinuing the current to the electric drive motor from the battery, impart the kinetic energy of the moving vehicle to drive the propelling motors as generators; and, the counter electromotive force (EMF) so produced in the motors applies a retarding force to the vehicle wheel drive and thus provides deceleration to the vehicle. This deceleration due to the counter EMF can produce a rapid rate of deceleration which would typically be experienced only by the vehicle operator applying the brakes. Thus, an electrically driven vehicle can experience rapid deceleration without the operator application of the brakes without activating the brake lights on the rear of the vehicle. This occurrence would fail to signal the human operator of a trailing vehicle that the lead vehicle was rapidly decelerating and thus can produce a hazardous situation and increase the likelihood of a vehicle collision.
The current desirability of increasing the number of electrically driven vehicles on public roads and decreasing the use of fossil fuel burning internal combustion engines for environmental reasons and the increased use of electric vehicles has thus created a need to provide an indication to the operator of a trailing vehicle that the electrically driven lead vehicle is decelerating and particularly without the operator of the lead vehicle applying the brakes as well as when the operator has applied the brakes. In this regard, it has become desirable to provide a means of utilizing the vehicle tail lights to indicate that the vehicle is rapidly decelerating, even when the vehicle operator is not applying the brakes.